Ionomeric, puncture resistant, thermoplastic bag

Abstract

A bag combination of: (A) a heat shrinkable film bag having a layer comprising: (a) 45-85 wt. % of a C 2 copolymer (55-98° C. m.p.) of C 6 or C 8 ; (b) 5-35 wt. % of a second C 2 α-olefin copolymer (115-128° C. m.p.); and (c) 10-50 wt. % of a third polymer (60-110° C. m.p.) of an unmodified or anhydride-modified, EVA, EAA or copolymer of C 2 and methacrylic acid or an alkyl acrylate; where a+b≧50 wt. % based on a+b+c; and the bag film has a total energy absorption≧0.70 Joule and a 90° C. shrink≧50%; and (B) a bag laminate which covers≧25% of the bag's surface; the laminate film comprising: 5-20 wt. % of (i) an ionomer; and 5-95 wt. % of (ii) a copolymer (55 to 95° C. m.p. and {overscore (M)} w /{overscore (M)} n of 1.5 to 3.5) of C 2 and a C 6 -C 8 α-olefin; 0 to 90 wt. % each of (iii) a copolymer of C 2 and a C 4 -C 8 α-olefin (100-125° C. m.p.); (iv) a copolymer (105 to 145° C. m.p.) of propylene and C 2 or C 4 ; and (v) a copolymer (125 to 135° C. m.p.) of C 2 and C 6 , C 8 or C 10 ; and (ii)+(iii)+(iv)+(v)≧80 wt. % based (i)+(ii)+(iii)+(iv)+(v); and the film and bag laminate has a total energy absorption of≧1.2 Joule.

What is claimed is:  
     
       1. A patch bag comprising: 
       (a) a bag having an inside surface and an, outside surface, said bag comprising a flexible, thermoplastic, biaxially stretched, heat shrinkable film having at least one layer comprising a blend of at least three copolymers comprising:  
       45 to 85 weight percent of a first polymer having a melting point of from 55 to 98° C. comprising at least one copolymer of ethylene and at least one comonomer selected from the group of hexene-1 and octene-1;  
       5 to 35 weight percent of a second polymer having a melting point of from 115 to 128° C. comprising at least one copolymer of ethylene and at least one a-olefin; and  
       10 to 50 weight percent of a third polymer having a melting point of from 60 to 110° C. comprising at least one unmodified or anhydride-modified copolymer of ethylene and a vinyl ester, acrylic acid, methacrylic acid, or an alkyl acrylate; wherein said first and second polymers have a combined weight percentage of at least 50 weight percent, said weight percentage being based upon the total weight of said first, second and third polymers; and wherein said film has a total energy absorption of at least 0.70 Joule and a shrinkage value at 90° C. of at least 50% in at least one of the machine and transverse directions; and  
       (b) a patch film attached to at least one surface of said bag and covering at least 25% of said surface, said patch film comprising a flexible, thermoplastic film having at least one layer comprising a blend of at least two polymers comprising:  
       5 to 20 weight percent of (i) an ionomer polymer;  
       5 to 95 weight percent of (ii) a copolymer of ethylene and at least one C 6  to C 8  a-olefin, wherein said copolymer (ii) has a melting point of from 55 to 95° C., and a {overscore (M)} w /{overscore (M)} n  of from 1.5 to 3.5;  
       0 to 90 weight percent of (iii) a copolymer of ethylene and at least one C4 to C 8  a-olefin, wherein said copolymer (iii) has a melting point of from 100 to 125° C.; and  
       0 to 90 weight percent of (iv) a copolymer of propylene and at least one monomer selected from the group of ethylene and butene-1, wherein said copolymer (iv) has a melting point of from 105 to 145° C.;  
       0 to 90 weight percent of (v) a copolymer of ethylene and at least one monomer selected from the group of hexene-1, octene-1 and decene-1, wherein said copolymer (v) has a melting point of from 125 to 135° C.; and wherein said polymers (ii), (iii), (iv), and (v) have a combined weight percentage of at least 80 weight percent; said weight percentages of polymers (i), (ii), (iii), (iv), and (v) being based upon the total weight of said polymers (i), (ii), (iii), (iv), and (v); and wherein said patch bag has a total energy absorption of at least 1.2 Joule through a patch covered bag area.  
     
     
       2. A patch bag, as defined in  claim 1 , wherein said patch film is biaxially stretched and heat shrinkable. 
     
     
       3. A patch bag, as defined in  claim 2 , wherein said patch film has a shrinkage value at 90° C. of at least 20% in at least one of the machine and transverse directions. 
     
     
       4. A patch bag, as defined in  claim 2 , wherein said patch film has a shrinkage value at 90° C. of at least 50% in at least one of the machine and transverse directions. 
     
     
       5. A patch bag, as defined in  claim 1 , wherein said patch film copolymer (iii) has a {overscore (M)} w /{overscore (M)} n  greater than 3.0. 
     
     
       6. A patch bag, as defined in  claim 1 , wherein said first polymer of said bag is a copolymer of ethylene and hexene-1. 
     
     
       7. A patch bag, as defined in  claim 1 , wherein said first polymer of said bag is a copolymer of ethylene and octene-1. 
     
     
       8. A patch bag, as defined in  claim 1 , wherein said first polymer of said bag is a copolymer of ethylene, butene-1 and hexene-1. 
     
     
       9. A patch bag, as defined in  claim 1 , wherein said first polymer of said bag has a melting point of 80 to 98° C. 
     
     
       10. A patch bag, as defined in  claim 1 , wherein said first polymer of said bag has a melting point of 55 to 95° C. 
     
     
       11. A patch bag, as defined in  claim 1 , wherein said ionomer comprises a zinc or sodium metal salt of an ethylene methacrylic acid copolymer. 
     
     
       12. A patch bag, as defined in  claim 1 , wherein said patch film is a monolayer film. 
     
     
       13. A patch bag, as defined in  claim 12 , wherein said patch film is a flattened tubular film. 
     
     
       14. A bag comprising: 
       (a) a bag having an inside surface and an outside surface, said bag comprising a flexible, thermoplastic, biaxially stretched, heat shrinkable film having at least one layer comprising a blend of at least three copolymers comprising:  
       45 to 85 weight percent of a first polymer having a melting point of from 55 to 98° C. comprising at least one copolymer of ethylene and at least one comonomer selected from the group of hexene-1 and octene-1;  
       5 to 35 weight percent of a second polymer having a melting point of from 115 to 128° C. comprising at least one copolymer of ethylene and at least one a-olefin; and  
       10 to 50 weight percent of a third polymer having a melting point of from 60 to 110° C. comprising at least one unmodified or anhydride-modified copolymer of ethylene and a vinyl ester, acrylic acid, methacrylic acid, or an alkyl acrylate; wherein said first and second polymers have a combined weight percentage of at least 50 weight percent, said weight percentage being based upon the total weight of said first, second and third polymers; and wherein said film has a total energy absorption of at least 0.70 Joule and a shrinkage value at 90° C. of at least 50% in at least one of the machine and transverse directions; and  
       (b) a first laminate film having a width equal to or greater than the bag flat width, said film attached to at least one surface of said bag and covering one side of said bag, said laminate film comprising a flexible, thermoplastic film having at least one layer comprising a blend of at least two polymers comprising:  
       5 to 20 weight percent of (i) an ionomer polymer,  
       5 to 95 weight percent of (ii) a copolymer of ethylene and at least one C 6  to C 8  a-olefin, wherein said copolymer (ii) has a melting point of from 55 to 95° C., and a {overscore (M)} w /{overscore (M)} n  of from 1.5 to 3.5;  
       0 to 90 weight percent of (iii) a copolymer of ethylene and at least one C 4  to C 8  a-olefin, wherein said copolymer (iii) has a melting point of from 100 to 125° C.; and  
       0 to 90 weight percent of (iv) a copolymer of propylene and at least one monomer selected from the group of ethylene and butene-1, wherein said copolymer (iv) has a melting point of from 105 to 145° C.;  
       0 to 90 weight percent of (v) a copolymer of ethylene and at least one monomer selected from the group of hexene-1, octene-1 and decene-1, wherein said copolymer (v) has a melting point of from 125 to 135° C.; and wherein said polymers (ii), (iii), (iv), and (v) have a combined weight percentage of at least 80 weight percent; said weight percentages of polymers (i), (ii), (iii), (iv), and (v) being based upon the total weight of said polymers (i), (ii), (iii), (iv), and (v); and wherein said bag has a total energy absorption of at least 1.2 Joule through a laminate film covered bag area.  
     
     
       15. A bag, as defined in  claim 14 , wherein said laminate film is biaxially stretched and heat shrinkable, having a shrinkage value at 90° C. of at least 20% in at least one of the machine and transverse directions. 
     
     
       16. A bag, as defined in  claim 15 , wherein said laminate film has a shrinkage value at 90° C. of at least 50% in at least one of the machine and transverse directions. 
     
     
       17. A bag, as defined in  claim 14 , further comprising a second laminate film, attached to at least one flatwidth surface of an opposing side of said bag relative to the side having said first laminate and said second laminate covering at least 25% of said surface, said second laminate film comprising a flexible, thermoplastic film having at least one layer comprising a blend of at least two polymers comprising: 
       5 to 20 weight percent of (i) an ionomer polymer;  
       5 to 95 weight percent of (ii) a copolymer of ethylene and at least one C 6  to C 8  a-olefin, wherein said copolymer (ii) has a melting point of from 55 to 95° C., and a {overscore (M)} w /{overscore (M)} n  of from 1.5 to 3.5;  
       0 to 90 weight percent of (iii) a copolymer of ethylene and at least one C 4  to C 8  a-olefin, wherein said copolymer (iii) has a melting point of from 100 to 125° C.; and  
       0 to 90 weight percent of (iv) a copolymer of propylene and at least one monomer selected from the group of ethylene and butene-1, wherein said copolymer (iv) has a melting point of from 105 to 145° C.;  
       0 to 90 weight percent of (v) a copolymer of ethylene and at least one monomer selected from the group of hexene-1, octene-1 and decene-1, wherein said copolymer (v) has a melting point of from 125 to 135° C.; and wherein said polymers (ii), (iii), (iv), and (v) have a combined weight percentage of at least 80 weight percent; said weight percentages of polymers (i), (ii), (iii), (iv), and (v) being based upon the total weight of said polymers (i), (ii), (iii), (iv), and (v); and wherein said bag has a total energy absorption of at least 1.2 Joule through a laminate bag area.  
     
     
       18. A bag, as defined in  claim 17 , wherein said second laminate film is biaxially stretched and heat shrinkable. 
     
     
       19. A bag, as defined in  claim 18 , wherein said second laminate film has a shrinkage value at 90° C. of at least 20% in at least one of the machine and transverse directions. 
     
     
       20. A bag, as defined in  claim 18 , wherein said second laminate film has a shrinkage value at 90° C. of at least 50% in at least one of the machine and transverse directions. 
     
     
       21. A bag, as defined in  claim 17 , wherein said second laminate has a width equal to said bag's flatwidth. 
     
     
       22. A bag, as defined in  claim 21 , wherein said second laminate has a width greater than said bag's flatwidth. 
     
     
       23. A bag, as defined in  claim 14 , wherein said first laminate has a width greater than said bag's flatwidth.